Impatiens has become an increasingly important ornamental crop. In 1970, in order to increase the germplasm pool for this crop, the U.S. Department of Agriculture introduced 23 Impatiens from New Guinea, 1 from Celebes and 1 from Java. H. F. Winters, Am. Hotic., 52, 923 (1973). New Guinea Impatiens (NGI) encompasses a group of interbreeding species that include I. schlecteri Warb., I. herzogii K.Schum, I. linearifolia Warb., I. mooreana Schltr., I. hawkeri Bull, and other species of the same geographic origin which are interfertile. NGI are diverse phenotypically, producing large flowers with colors ranging from white to various shades of lavender, red, pink and orange. The leaves are of various shapes and sizes, with and without variegations. C. Grey-Wilson, Kew Bulletin, 34, 661 (1979). Although diverse phenotypically, members of NGI are interfertile and generally have a 2n chromosome number of 32. T. Arisumi, J. Hered., 64: 77 (1973).
Java and Celebes Impatiens are known as I. platypetala Lindl. and I. platylpetala aurantiaca Steen, respectively. K. Han et al., Scientia Horticulturae, 32, 307 (1987). The introduced species from New Guinea, Celebes and Java generally have been found to cross readily among themselves, even though their somatic chromosome numbers vary. D. W. Pasutti et al., Can. J. Bot., 58, 384, (1980); J. L. Weigle et al., Acta Horticulureae, 63, 109 (1976); A. R. Beck et al., Can. J. Bot., 52, 923 (1974); T. Arisumi, HortScience, 95: 478 (1974).
The expected merger of New Guinea, Celebes and Java into Impatiens of African origin, such as the Sultana Impatiens (I. wallerana), has not occurred because of incompatibility barriers. A. R. Beck et al., Can. J. Bot., 52, 923 (1974). Despite incompatibility with Impatiens of African origin, NGI cultivars have become popular in their own right as ornamentals. The NGI group produces a wider array of leaf variegation and larger flowers with more brilliant colors than the nonvariegated and seed-propagated species of African origin.
L. C. Stephens, HortScience, 20, 362 (1985), which is incorporated herein by reference, teaches methods for the in vitro propagation of NGI that offers the advantages of a continuous source of vegetative shoots and the production of more shoots per unit of time than traditional vegetative propagation methods. K. Han et al., Scientia Horticulturae, 32, 307 (1987), which is incorporated herein by reference, teach methods for the in vitro propagation of Celebes, Java, and NGI and interspecific hybrids of Celebes or Java and NGI.
Commercial bedding Impatiens of African origin, such as I. wallerana, are known which produce more than 5 petals per flower (Plant Patent No. 7,690). NGI cultivars, however, typically produce flowers having five petals per flower. The cultivar "Aurora", described in Plant Patent No. 6298, has been observed to occasionally, but not consistently, produce flowers having a sixth small partial petal per flower. The breeding of NGI cultivars which produce one or more flowers having at least seven petals per flower would offer a choice of unique flower form to compliment the presently available and popular NGI cultivars having five petals per flower.